Telephone networks provide a means for communicating orally with other people over large distances. The classic PSTN (Public Switched Telephone Network) is increasingly replaced and/or augmented by newer telephone network types, such as e.g. ISDN networks, GSM and UMTS cell-phone networks as well as IP Telephony, also known as Voice over Internet Protocol (VoIP) networks. At the same time, the variety of telephone devices and other voice communication devices used as interfaces to telephone networks is increasing. These developments generally increase system complexity, and it is an ongoing challenge for the telephone industry to provide easy-to-use systems and devices to the users and at the same time allow the users to effortlessly switch between different devices and/or different modes of using the devices. Known systems thus typically fail to provide desired handling flexibility to the user and/or require the execution of complicated manual configuration or connection procedures to achieve such flexibility.
US patent application 2011/306393 discloses a headset system with a headset base unit and a wireless headset. The headset base unit comprises a housing, a headset holder and a display device with a touch-screen display. When not in use, the headset may be arranged on the headset holder. The headset system can be connected to a number of telecommunication terminals or devices, such as a desk phone, a PC and a mobile phone. The headset base unit also comprises a speaker for generating an audible feedback to the user when operating the touch display and to signal e.g. an incoming soft phone call on the PC. The desk phone and the PC may each be connected to the headset base unit via wires, while the mobile phone may be connected via a wireless connection, such as e.g. a Bluetooth™ connection. The wireless connection between the headset and the headset base unit may e.g. be a DECT connection or a Bluetooth connection. The headset may also be connected directly to the mobile phone, e.g. via a Bluetooth connection. The desk phone may be a DECT wireless telephone with a phone base and a wireless handset connected thereto via a DECT connection. The headset base unit and the phone base may further be connected via a second DECT connection, and the headset base unit and the handset may further be connected via a third DECT connection. The disclosed headset system is thus simultaneously connectable to three different telecommunication devices, namely the desk phone, the PC and the mobile phone. The user can accept, reject and initiate calls via respective user interfaces provided on the headset and on the headset base unit. Similar considerations apply to a wireless headset connected to a base station.
PCT patent application WO 2013/087099 discloses a similar headset system wherein the touch-screen display of the headset base unit is replaced by a device holder in which a mobile communication device can be placed and used for controlling the telecommunication devices via the headset base unit.
The above patent applications do not disclose means for handling a number of ambiguous and/or conflict situations that can occur in daily use of the headset systems, in particular when they are used together with mobile phones or other mobile telecommunication devices that can be easily taken outside the wireless ranges of the headsets and/or the headset base units. Examples of such situations will become clear from the following description of the present invention.